Technical Guide
Sleeves:
Los Angeles Sleeve Co.manufactures centrifugal cast iron cylinder sleeves for all popular
makes and models of outboards. Engine rebuilders find they can rely on the quality and workmanship of LASCO
outboard cylinder sleeves, and their use saves them time and money. The centrifugal castings used in the man-
ufacture of these sleeves are made from an alloy of carbon chrome and molybdenum of 200 “Brinell” hardness,
which insures ease in installation, trouble free boring and a dependable long life engine.
Centerless grinding of outside diameters of LASCO sleeves provides for perfect roundness and exact size which
is controlled by rigid inspection of one-half thousandth of an inch. We invite comparison of our sleeves with other
leading makes for size, roundness and finish.
Each cylinder sleeve is designed to best suit its designated cylinder. Three concepts are integrated in the
designing and manufacturing of a sleeve:
1)The retained strength of a cylinder after the sleeve is installed.
2)Ease of installation for the rebuilder.
3)The ability to bore to the maximum amount of oversize pistons available.
The Star column, next to the sleeve part number, will help the rebuilder identify the cylinder that is to be sleeved.
The Star column designation will also help the rebuilder to determine the proper installation procedure.
Starred Column Code Explanations:
AC-Original cylinder bore is alloy-chrome plated, Nikasil, or electrofused. The cylinder must be bored to
accept the new cylinder sleeve.
CS-Original block has a cast-in sleeve liner in the cylinder.The cylinder must be bored out to accept the
new cylinder sleeve. The cast-in liner will be bored completely out of the cylinder. Do not try to push
out the cast-in liner, cylinder damage may be the result.
CI-Original block has a cast-in liner in the cylinder. The cylinder must be bored to accept the new cylinder
sleeve. When using a CI style sleeve the cast-in liner will not be completely removed. The sleeve is
designed to insert into the iron lined cylinder.
RS-Original block has a replacement sleeve. Heat the cylinder to remove the sleeve. Reheat the cylinder
to install the new cylinder sleeve.
CC-Original barrel is cast-iron. The cylinder must be bored to accept the new cylinder sleeve.
General Rules for Sleeve Installation:
These tips are intended to be a guide for installing sleeves into cylinders. There are always exceptions to the
rule and care must be taken on special applications.
ALWAYS WAIT UNTIL THE SLEEVE ARRIVES BEFORE BEGINNING ANY
MACHINE WORK. NEVER ASSUME THAT THE STATED MODEL AND YEAR
OF THE CYLINDER IS CORRECT. ALWAYS CHECK TO SEE IF THE SLEEVE
PORTS MATCH THE CYLINDER PORTS.
1.Interference fit for cylinder sleeve to aluminum bore is .004.
2.Interference fit for cylinder sleeve to a cast iron bore is .002 to .003.
3.Installation of flanged type sleeves follow the same rules, but the top of the cylinder must have a
countersink to the correct depth to accept the flanged sleeve. .000 to .001 interference fit on the flange
diameter is recommended.
4.Heating the cylinder for 45 minutes to one hour at 350 degrees to 450 degrees is preferable.
5.The sleeve should slide in very easily when the cylinder is properly heated. Freeze shrinking the sleeve
is optional. (Some machinists believe this assists installation of the sleeve.)
6.REMEMBER:Rap or press the sleeve down while the cylinder is cooling down. Use a hydraulic press
for this procedure.
7.Milling the top deck of the cylinder always adds a quality touch. A caution here, some cylinders may not
be able to have the top surface decked.
8.For 2-stroke cylinders, blending or matching the ports is recommended for proper fuel flow